Why do people with hemophilia continue to bleed?

Hemophilia
means that the fibrin net does not get made properly. Without the fibrin
net, the platelet plug falls out and bleeding continues.

Why does this happen?
With hemophilia, one of the 14 clotting factors does not work properly.
When a blood vessel is torn, usually the blood vessel constricts and
the platelets make a plug. The clotting factors start giving each other
directions: factor III, for example, directs factor VII. But then something
doesn't work right. Somewhere along the way, using the relay race example,
one of the factors drops the relay baton - the directions for blood
clotting. It does not alert the next factor in line, so the rest of
the factors can't continue their work. The relay race is over. The creation
of the fibrin net stops and the bleeding continues.